High temperature thermosets and ceramics derived from linear carborane-(siloxane or silane)-acetylene copolymers

ABSTRACT

This invention relates to a new class of novel inorganic-organic hybrid thermosetting polymers and ceramics that are formed from novel linear polymers of varying molecular weight and varying carborane content. These novel organoboron thermoset polymers and ceramics contain an unsaturated cross-linked moiety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a new class of novel inorganic-organic hybridpolymers that are formed from linear inorganic-organic hybrid polymersof varying molecular weight. These new high temperature oxidativelystable thermosetting polymers are formed from linear polymeric materialshaving repeat units that contain at least one alkynyl group forcross-linking purposes and at least one bis(silyl orsiloxanyl)carboranyl group and wherein the carborane content of thethermosets can be varied. These novel thermosetting polymers can befurther converted into ceramics at elevated temperatures.

2. Description of the Related Art

The cross linking of acetylenic polymers has been demonstrated by Neenanet al. in Hypercross-Linked Organic Solids: Preparation fromPoly(aromatic diacetylenes) and Preliminary Measurements of TheirYoung's Modulus, Hardness, and Thermal Stability published in 21MACROMOLECULES 3525-28 (1988), incorporated herein by reference. Othersimilar cross linking reactions are demonstrated by Callstrom et al. inPoly[ethynlyene(3-n-butyl-2,5-thiophenediyl)-ethynylene]: A SolublePolymer Containing Diacetylene Units and Its Conversion to a HighlyCross-Linked Organic Solid published in 21 MACROMOLOCULES 3528-30(1988), incorporated herein by reference. The recent literature reflectscontinuing major research efforts to advance fundamental knowledge inhigh temperature material design. See K. J. Wynne and R. W. Rice,Ceramics Via Polymer Pyrolysis 14 ANN. REV. MAT. SCI. 297 (1984)incorporated herein by reference in its entirety and for all purposes.In the search for high temperature oxidatively stable materialsconsiderable attention has been given to polymers containing boronwithin the polymer. It has been known that the addition of a carboranewithin a siloxane polymer significantly increases the thermal stabilityof such siloxane polymers.

The thermal properties of various siloxane polymers are given by PETARDVORNIC ET AL. in HIGH TEMPERATURE SILOXANE ELASTOMERS published byHuthig & Wepf Verlag Basel, New York (1990) on pp. 277 in FIG. 5.7 andon pp.282 in FIG. 5.12 and by Edward N. Peters inPoly(dodecacarborane-siloxanes) published in J. MACROMOL. SCI. REV.MACROMOL. CHEM., C17(2) on pp. 190-199 in FIGS. 3,4,5,6,7,10 and 12,each reference being incorporated herein by reference in its entiretyand for all purposes. See also Maghsoodi et al. in Synthesis and Studyof Silylene-Diacetylene Polymers published in 23 MACROMOLECULES pp. 4486(1990), incorporated herein by reference in its entirety and for allpurposes.

Many of the carborane polymers manufactured are cited in various U.S.patents. See, for instance, the following U.S. Pat. Nos.: 5,348,917;5,292,779; 5,272,237; 4,946,919; 4,269,757; 4,235,987; 4,208,492;4,145,504; 3,661,847; 3,542,730; 3,457,222; and 3,234,288, each patentbeing incorporated herein by reference in its entirety and for allpurposes.

There is a need for oxidatively stable materials that have thermosettingproperties for making rigid components therefrom, such as engine parts,turbine blades and matrices. These components must withstand hightemperatures and be oxidatively stable and have sufficient strength towithstand the stress put on such components.

There is a need for carborane-silane and/or carborane-siloxanecross-linked thermosetting polymeric materials wherein the carboranecontent of the thermosetting polymers can be varied and that show hightemperature stability where weight percentage loss is limited to 50% orless from the original total weight or where the weight percentage lossis limited to 40% or less after formation of the thermoset when heatedin excess of 400° to 700° C. in an oxidative environment.

There is a need for carborane-silane and/or carborane-siloxanecross-linked thermosetting polymeric materials wherein the carboranecontent of the thermosetting polymers can be varied and that show hightemperature stability where weight percentage loss is limited to 30% orless from the original total weight or where the weight percentage lossis limited to 15% or less after formation of the thermoset when heatedin excess of 400° to 700° C. in an oxidative environment.

There is a need for carborane-silane and/or carborane-siloxanecross-linked thermosetting polymeric materials wherein the carboranecontent of the thermosetting polymers can be varied and that show hightemperature stability where weight percentage loss is limited to 20% orless from the original total weight or where the weight percentage lossis limited to 10% or less after formation of the thermoset when heatedin excess of 400° to 700° C. in an oxidative environment.

In addition, there is a need for carborane-silane and/orcarborane-siloxane cross-linked thermosetting polymeric materials thatbehave more as rigid materials and less as elastomeric materials andwherein the carborane content of the thermosets can be varied.

There is a further need to provide carborane-silane and/orcarborane-siloxane thermosetting materials wherein the carborane contentwithin the thermosets can be varied to provide maximum thermal stabilityand minimum cost.

In addition, a majority of the carborane-siloxane and/orcarborane-silane polymers made by others show elastomeric propertiesrather than properties of more rigid polymeric products likethermosetting polymers or ceramics. Thus, in addition to thermalstability, there is also a need for polymers that behave more asthermosets and ceramics, upon further polymerization, and less likeelastomeric polymers.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to providecross-linked carborane-silane-alkenyl and/or carborane-siloxane-alkenylthermosetting polymers or thermosets that show high temperaturestability where weight percentage loss is limited to 50% or less fromthe original total weight or where the weight percentage loss is limitedto 40% or less after formation of the thermoset when heated in excess of400° to 700° C. in an oxidative environment and wherein the content ofcarborane within the polymers can be varied.

It is therefore an object of the present invention to providecross-linked carborane-silane-alkenyl and/or carborane-siloxane-alkenylthermosetting polymers or thermosets that show high temperaturestability where weight percentage loss is limited to 30% or less fromthe original total weight or where the weight percentage loss is limitedto 15% or less after formation of the thermoset when heated in excess of400° to 700° C. in an oxidative environment and wherein the content ofcarborane within the polymers can be varied.

It is therefore an object of the present invention to providecross-linked carborane-silane-alkenyl and/or carborane-siloxane-alkenylthermosetting polymers or thermosets that show high temperaturestability where weight percentage loss is limited to 20% or less fromthe original total weight or where the weight percentage loss is limitedto 10% or less after formation of the thermoset when heated in excess of400° to 700° C. in an oxidative environment and wherein the content ofcarborane within the polymers can be varied.

It is therefore yet another object of the present invention to providelinear carborane-silane-alkenyl and/or carborane-siloxane-alkenylthermosetting polymers wherein the carborane content within the polymerscan be varied to provide maximum thermal stability and minimum cost.

These and other objects are accomplished by forming linear polymershaving the composition: ##STR1## wherein n, n', u, u', x, x', y, y' andy" are integers, wherein the ratio y'/y≠0, wherein A is selected fromthe group consisting of O, an aliphatic bridge, an aryl bridge ormixtures thereof and E is selected from the group consisting of O, analiphatic bridge, an aryl bridge or mixtures thereof. In addition, Eand/or A may further be selected from the group consisting of analiphatic bridge of about 1 to about 20 carbon atoms, an aryl bridge ofabout 5 to 40 carbon atoms, or mixtures thereof. Furthermore, A and Emay be the same or different. Further heating or light exposure formsthe desired thermosets. Further heating of the thermosets forms thedesired ceramics.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and several of theaccompanying advantages thereof will be readily obtained by reference tothe following detailed description when considered in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a differential scanning calorimetry (DSC) plot of heat flowversus temperature in nitrogen obtained at an exemplary heating rate of10° C./minute.

FIG. 2 is a thermogravimetric analytical (TGA) plot of weight % versustemperature in nitrogen obtained on the first heating cycle (e.g.heating from 50° C. to 1000° C. at 10° C./minute).

FIG. 3 is a TGA plot of weight versus temperature in an oxidizingenvironment (air), subsequently obtained on the second heating cycle(e.g. heating from 100° C. to 1000° C. at 10° C./minute).

FIGS. 1, 2, and 3 are for the polymer having the formula: ##STR2## wheren'=n=2, q=q'=10, u=u'=x=x'=1, R¹ =R² =R³ =R⁴ =R⁵ =R⁶ =R⁷ =R⁸ =CH₃ andthe ratio y'/y on average is equal to about 1.0.

FIG. 4 is a differential scanning calorimetry (DSC) plot of heat flowversus temperature in nitrogen obtained at an exemplary heating rate of10° C./minute.

FIG. 5 is a thermogravimetric analytical (TGA) plot of weight % versustemperature in nitrogen obtained on the first heating cycle (e.g.heating from 50° C. to 1000° C. at 10° C./minute).

FIG. 6 is a TGA plot of weight versus temperature in an oxidizingenvironment (air), subsequently obtained on the second heating cycle(e.g. heating from 100° C. to 1000° C. at 10° C./minute).

FIGS. 4, 5, and 6 are for the polymer having the formula: ##STR3## wheren'=n=2, q=q'=10, u=u'=x=x'=1, R¹ =R² =R³ =R⁴ =R⁵ =R⁶ =R⁷ =R⁸ =CH₃ andthe ratio y'/y on average is equal to about 3.0.

FIG. 7 is a differential scanning calorimetry (DSC) plot of heat flowversus temperature in nitrogen obtained at an exemplary heating rate of10° C./minute.

FIG. 8 is a thermogravimetric analytical (TGA) plot of weight % versustemperature in nitrogen obtained on the first heating cycle (e.g.heating from 50° C. to 1000° C. at 10° C./minute).

FIG. 9 is a TGA plot of weight versus temperature in an oxidizingenvironment (air), subsequently obtained on the second heating cycle(e.g. heating from 100° C. to 1000° C. at 10° C./minute).

FIGS. 7, 8, and 9 are for the polymer having the formula: ##STR4## wheren'=n=2, q=q'=10, u=u'=x=x'=1, R¹ =R² =R³ =R⁴ =R⁵ =R⁶ R⁷ =R⁸ =CH₃ and theratio y'/y on average is equal to about 9.0.

FIG. 10 is a differential scanning calorimetry (DSC) plot of heat flowversus temperature in nitrogen obtained at an exemplary heating rate of10° C./minute.

FIG. 11 is a thermogravimetric analytical (TGA) plot of weight % versustemperature in nitrogen obtained on the first heating cycle (e.g.heating from 50° C. to 1000° C. at 10° C./minute).

FIG. 12 is a TGA plot of weight versus temperature in an oxidizingenvironment (air), subsequently obtained on the second heating cycle(e.g. heating from 100° C. to 1000° C. at 10° C./minute).

FIGS. 10, 11, and 12 are for the polymer having the formula: ##STR5##where n'=n=2, q=q'=10, u=u'=x=x'=1, R¹ =R² =R³ =R⁴ =R⁵ =R⁶ =R⁷ =R⁸ =CH₃and the ratio y'/y on average is equal to about 19.0.

FIG. 13 is a TGA of the thermoset made from the linear polymer of FIGS.1, 2, and 3. FIG. 14 is a TGA of the thermoset made from the linearpolymer of FIGS. 4, 5, and 6. FIG. 15 is a TGA of the thermoset madefrom the linear polymer of FIGS. 7, 8, and 9. FIG. 16 is a TGA of thethermoset made from the linear polymer of FIGS. 10, 11, and 12. Thethermosets of FIGS. 13. 14, 15 and 16 have the formula: ##STR6## whereinthe values of n, n', q, q' x, x', y, y' and y" are unchanged and theidentities of R¹ =R² =R³ =R⁴ =R⁵ =R⁶ =R⁷ =R⁸ =CH₃ as previouslyindicated and the ratio y'/y is also unchanged, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description of the invention is provided to aidthose skilled in the art in practicing the present invention. However,the following detailed description of the invention should not beconstrued to unduly limit the present invention. Variations andmodifications in the embodiments discussed may be made by those ofordinary skill in the art without departing from the scope of thepresent inventive discovery.

This invention relates to a new class of novel cross-linkedthermosetting polymers (35) made by the following general reactionscheme: ##STR7## wherein (1) n and n' are integers from 1 to 12 and u,u', y, y' and y" are positive integers;

(2) ##STR8## represent unconjugated acetylenic moieties or conjugatedacetylenic moieties when n and n' are integers greater than 1,respectively;

(3) R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are selected from the groupconsisting of saturated aliphatic, unsaturated aliphatic, aromatic,fluorocarbon moieties and mixtures thereof;

(4) ##STR9## represents said carboranyl group; (5) q and q' are integersfrom 3 to 16;

(6) x and x' represent integers greater than or equal to zero(x≧0;x'≧0);

(7) A is selected from the group consisting of O, an aliphatic bridge,an aryl bridge or mixtures thereof; and

(8) E is selected from the group consisting of O, an aliphatic bridge,an aryl bridge or mixtures thereof;

(9) wherein E and A may be the same or different;

(10) wherein said carboranyl group represents a carboranyl groupselected from the group consisting of 1,7-dodecacarboranyl;1,10-octacarboranyl; 1,6-octacarboranyl; 2,4-pentacarboranyl;1,6-tetracarboranyl; 9-alkyl-1,7-dodecacarboranyl;9,10-dialkyl-1,7-dodecacarboranyl; 2-alkyl-1,10-octacarboranyl;8-alkyl-1,6-octacarboranyl; decachloro-1,7-dodecacarboranyl;octachloro-1,10-octacarboranyl; decafluoro-1,7-dodecacarboranyl;octafluoro-1,10-octacarboranyl; closo-dodeca-ortho-carboranyl;closo-dodeca-meta-carboranyl; closo-dodeca-para-carboranyl and mixturesthereof; and

(11 ) wherein ##STR10## represent cross-linked alkenyl moieties andwherein n and n' are as previously indicated.

The conversion of the linear polymers (20) to the cross-linked polymers(35) is accomplished either by exposing the linear polymers (20) to heator light. Thermal conversion of the carbon-to-carbon triple bonds inpolymers (20) to form the thermosetting polymers (35) is dependent onboth the curing temperature and the curing time. The heating of thelinear polymers (20) is carried out over a curing temperature rangesufficient for the cross-linking of the carbon-to-carbon triple bonds ofthe individual linear polymers (20) to occur resulting in the formationof a single mass of cross-linked polymers (35). The heating of thelinear polymers (20) is carried out over a curing time sufficient forthe cross linking of the carbon-to-carbon triple bonds of the individuallinear polymers (20) to occur resulting in the formation of thecross-linked polymers (35). In general, the curing time is inverselyrelated to the curing temperature. The typical temperature range, thepreferred temperature range, the more preferred temperature range andthe most preferred temperature range for the thermal conversion oflinear polymers (20 ) to the cross-linked thermoset polymers (35) are,typically, 150°-450° C., 200°-400° C., 225°-375° C. and 250°-350° C.,respectively. The typical curing time, the preferred curing time, themore preferred curing time, and the most preferred curing time for thethermal conversion of linear polymers (20) to the cross-linked thermosetpolymers (35) are, typically, 1-48 hours, 2-24 hours, 8-12 hours and 1-8hours, respectively.

The photocrosslinking process, of converting the carbon-to-carbon triplebonds of the linear polymers (20) into unsaturated cross-linked moietiesnecessary for forming the thermosetting polymers (35), is dependent onboth the exposure time and the intensity of the light used during thephotocrosslinking process. Ultraviolet (UV) light is the most preferredwavelength of light used during the photocrosslinking process. Theexposure time of the linear polymers (20) to the UV light is inverselyrelated to the intensity of the UV light used. The exposure time to theUV or to other light used is that time which is sufficient for thecarbon-to-carbon triple bonds of the linear polymers (20) to be crosslinked to form the thermosetting polymers (35). The intensity of thelight used is that intensity which is sufficient for thecarbon-to-carbon triple bonds of the linear polymers (20) to be crosslinked to form the thermosetting polymers (35). Furthermore, thewavelength of the light used is not limited to the UV range. Thewavelength of light used is that wavelength which is sufficient for thecarbon-to-carbon triple bonds of the linear polymers (20) to be crosslinked to form the thermosetting polymers (35). The typical exposuretime, the preferred exposure time, the more preferred exposure time andthe most preferred exposure time are, typically, 1-100 hours, 24-36hours, 12-24 hours and 4-8 hours, respectively. Examples of theconversion of linear polymers (20) to the cross-linked thermosets (35)are given infra.

The general chemical scheme for synthesizing these novel linear polymers(20) is represented by the exemplary synthesis of (20') given below:##STR11## wherein: (1) n=n'=2, u=u'=x=x'=1, y, y' and y" are positiveintegers;

(2) ##STR12## represents a conjugated acetylenic moiety where n=n'=2;(3) R¹ =R² =R³ =R⁴ =R⁵ =R⁶ =R⁷ =R⁸ =CH₃ ;

(4) ##STR13## represents said carboranyl group; and (5) q=q'=10;

(6) Z is selected from the group consisting of F, Cl, Br and I;

(7) ##STR14## represents a dilithio salt where n=2 or n'=2; (8) n-BuLirepresents n-butyllithium;

(9) A is an oxygen atom; and

(10) E is an oxygen atom.

Given the general scheme, step 1 involves forming a salt, for example,the dilithio salt of butadiyne by reacting 4 equivalents of n-BuLi withhexachlorobutadiene. Note that Reagents of the following general formulamay be used: ##STR15## wherein M is selected from the group consistingof Li, Na, K and MgX' where X' is selected from the group consisting ofF, Cl, Br and I. To form the polymer (20'), wherein y'/y=1.0, step 2involves reacting the dilithiobutadiyne (15') produced in step 1 withcompounds (5') and (10') wherein the molar concentration of (5') equalsthe molar concentration of (10') and wherein the molar concentrations of(5') and (10'), respectively, equal one-half (1/2) the molarconcentration of the dilithiobutadiyne (15'). In general, the followingconcentrations are used:

(i) molar conc. of (5')+molar conc. of (10')=molar conc. of (15')

(ii) the ratio of y'/y=(molar conc. of (5')/(molar conc. of (10')).

For the formation of polymer (20), the present invention makes the ratioof y'/y variable by the use of appropriate molar ratios of compoundshaving the formula (5) and (10), infra. In general, the ratio of y'/y isequal to the molar concentration of (5) used divided by the molarconcentration of (10) used in forming (20). Thus, if equimolar amountsof (5) and (10), infra, are used, then the ratio of y'/y is about 1.0.If the molar ratios of (5) and (10), infra used are 1 to 99,respectively, then the ratio of y'/y is about 0.01 in the formed product(20). Typically, the ratio y'/y is between about 0.01 to about 50. Moretypically, the ratio y'/y is between about 1 to about 25. Mosttypically, the ratio y'/y is between about 5 to about 15. Preferably,the ratio y'/y is between about 8 to about 12. Most preferably, theratio y'/y is about 9.

It should be noted that if trichloroethylene is used in step 1 insteadof hexachlorobutadiene, a salt of ethyne or acetylene is formed in step1 where n=1. Consequently, an ethynyl moiety is incorporated into thepolymer (20) produced in step 2 where n=n'=1. By usinghexachlorobutadiene in step 1, the salt of butadiyne is formed wheren=2. In turn, a butadiyne moiety is incorporated into polymer (20')where n=n'=2. In order to form a polymer where n=3, a salt of hexatriyneneeds to be formed in step 1. The synthesis of the disodium salt ofhexatriyne is given in the article by Bock and Seidl, d-Orbital Effectsin Silicon Substituted π-Electron Systems. Part XII. Some SpectroscopicProperties of Alkyl and Silyl Acetylenes and Polyacetylenes, J. CHEM.Soc. (B), 1158 (1968) at pp. 1159, incorporated herein by reference inits entirety and for all purposes. Thus, by forming the appropriatealkynyl salt, the length of the alkynyl moiety, represented by the valueof n and n', incorporated into the polymer formed in step 2 can becontrolled. Typically, the value of n and n' can be varied from 1 to 12.Acetylenic derivatives having the general formula H(C.tbd.C)_(n) H canbe readily converted into the dilithio salts by reacting withn-butyllithium. The respective dilithio salts, with values of n varyingfrom 1 to 12, can then be incorporated into the backbone of polymers(20) as shown in the aforementioned step 2. The value of n and n' can bevaried, typically, from 1 to 12, more often from 1 to 10 and 1 to 8,most often from 1 to 6 and, in particular, from 1 to 3 and 1 to 2.Acetylenic derivatives having the general formula H(C.tbd.C_(n) H can bereadily formed by the synthesis given by Eastmond et al. in Silylationas a Protective Method for Terminal Alkynes in Oxidative Couplings--AGeneral Synthesis of the Parent Polyynes, 28 TETRAHEDRON 4601 (1972),incorporated herein by reference in its entirety and for all purposes.

Furthermore, a variety of compounds can be produced that have structuressimilar to that of compound (10') shown in step 1. One variationincludes replacing the methyl groups attached to the Si with otherhydrocarbon or aromatic moieties. Typical reactions synthesizingdisubstituted dichloro silanes of varying size (varying values of u) andhaving different R groups are known in the art: ##STR16## where M' is agroup I metal or alloy. The above reaction is cited by ZELDIN ET AL.(EDITORS) in INORGANIC AND ORGANOMETALLIC POLYMERS, published byAmerican Chemical Society, Washington, D.C. (1988) at 44 and 90. Thevalue of u can be varied, typically, from 1 to 1000, more often from 1to 500 and 1 to 250, most often from 1 to 100 and 1 to 10, and, inparticular, from 1 to 6. Another variation includes controlling thevalues of x in addition to that of u.

Synthesis of a variation of compound (10') where u=1 and x=0 and E=O andZ=Cl is given by Papetti et al. in A New Series of Organoboranes. VI.The Synthesis and Reactions of Some Silyl Neocarboranes, 3 INORG. CHEM.1448 (1964) at 1449 under the caption"C,C'-Bis(methyldichlorosilyl)neocarborane (IV)", incorporated herein byreference in its entirety and for all purposes. The synthesis ofcompound (10') where u=1 and x=1 and E=O and Z=Cl is given by Papetti etal. in A New Series of Organoboranes. VII. The Preparation ofPoly-m-carboranylenesiloxanes, 4 JOURNAL OF POLYMER SCIENCE: PART A-1,1623 (1966) at 1630 under the caption "Compound (VII)", incorporatedherein by reference in its entirety and for all purposes. Synthesis of avariation of compound (10') where u=1 and x=2 and E=O and Z=Cl is givenby Scott et al. in Icosahedral Carboranes. XV. MonomericCarboranylenesiloxanes, 9 INORG. CHEM. 2597 (1970) at 2599 under thecaption "1,7-Bis(5-chlorohexamethyltrisiloxanyl)-m-carborane (IV)",incorporated herein by reference in its entirety and for all purposes.

While leaving u=1, the value of x can be varied, typically, from 0 to1000, more often from 0 to 500 and 0 to 250, most often from 0 to 10,and, in particular, from 0 to 2 by the following proposed reactionscheme (i.e. the length of the polymer chain within compound (10) isvaried according to the following reaction): ##STR17## where x and x'are integers greater than or equal to 0 (x≧0; x'≧0), u' is a positiveinteger and A is an oxygen atom and E is an oxygen atom.

The value of x can be iteratively increased by reacting compounds (5)and (10) wherein u=u'=1 until the desired integral value of x isobtained; thereafter, further reacting the reaction product (10") withcompound (5) wherein u' is an integer greater than 1 thereby formingproduct (10) wherein the value of u can be varied to integral valuesgreater than 1 and wherein the value of x has been adjusted to a desiredintegral value greater than 1. Note that reaction product (10") isanalogous to reactant (10) wherein the values of integrals u and x havebeen varied.

However, A may be selected from the group consisting of O, an aliphaticbridge, an aryl bridge or mixtures thereof. A may further be selectedfrom the group consisting of an aliphatic bridge of about 1 to about 20carbon atoms, an aryl bridge of about 5 to about 40 carbon atoms, ormixtures thereof. Furthermore, E may be selected from the groupconsisting of O, an aliphatic bridge, an aryl bridge or mixturesthereof. E may further be selected from the group consisting of analiphatic bridge of about 1 to about 20 carbon atoms, an aryl bridge ofabout 5 to about 40 carbon atoms, or mixtures thereof. In addition, Aand E may be the same or different. An exemplary synthesis of compound(10) is shown by the synthesis of exemplary compound (100). Synthesis ofexemplary compound (100) wherein R¹, R², R³ and R⁴ are --CH₃, wherein Eis --CH₂ CH₂ CH₂ CH₂ --, wherein x= 2, u=1, and q=q'=10 is given inEXAMPLE 10, infra.

The synthesis of (5) is given below: ##STR18## wherein x'=x+1 and A isan oxygen atom and wherein R⁵, R⁶, R⁷, and R⁸ may be the same ordifferent.

For the case where A is not an oxygen atom, the synthesis of (5) isgiven below: ##STR19## wherein M is selected from the group consistingof Li, Na, K and MgX' where X' is selected from the group consisting ofF, Cl, Br and I, wherein R⁷ and R⁸ may be the same or different and x isa positive integer. Where the ratio of the molar concentration of (70)to the molar concentration of (80) is equal to about one-half, the valueof x is about 1. Where the ratio of the molar concentration of (70) tothe molar concentration of (80) is greater than one-half but less than1, the value of x is greater than 1. When A is not an oxygen atom, toform compound (5), the value of x can be controlled by selecting theappropriate ratio of the molar concentration of (70) to the molarconcentration of (80). If the ratio is selected according to 1/2≦(molarconcentration of (70) / molar concentration of (80))<1, then theintegral value of x obtained in compound (5) is proportional to theratio of the molar concentration of (70) to the molar concentration of(80).

A may be selected from the group consisting of O, an aliphatic bridge,an aryl bridge or mixtures thereof. A may further be selected from thegroup consisting of an aliphatic bridge of about 1 to about 20 carbonatoms, an aryl bridge of about 5 to about 40 carbon atoms, or mixturesthereof.

Following the scheme in the aforementioned steps 1 and 2, the novellinear polymers (20) can be formed by reacting a salt of an alkyne or arespective Grignard reagent with compounds (5) and (10): ##STR20##wherein E is selected from the group consisting of O, an aliphaticbridge, an aryl bridge or mixtures thereof and wherein A is selectedfrom the group consisting of O, an aliphatic bridge, an aryl bridge ormixtures thereof.

These novel linear polymers (20) exhibit sufficiently low viscositieseither at room temperature or at their respective melting points (i.e.20°-70° C.) to readily fill complex dies or shapes for forming partstherefrom. In addition, these polymers (20) can be further polymerizedinto thermosets and ceramics that form rigid shapes which areoxidatively stable at high temperatures above 600° C.

The following examples outline preferred embodiments of the presentinvention.

EXAMPLE 1

Compound (30) is synthesized according to the method of Papetti &Heying. See S. Papetti et al. 3 INORG CHEM 1448 (1964). The structure ofcompound (30) is given below: ##STR21## According to the method ofPapetti et al., a 100 ml round bottom 3-neck flask was fitted with anaddition funnel and septa, flushed with argon, and flamed. The reactionwas carried out under an inert atmosphere (argon). Butyllithium (18.0ml/ 2.5M in hexanes, 44.9 mmol) was cooled to -78° C. Meta-carborane(2.5902 g, 18.0 mmol) in 10 ml THF was added dropwise. A white solid(dilithiocarborane) formed and the reaction was allowed to warm toambient temperature. After cooling the reaction mixture back to -78° C.,dichlorodimethylsilane (5.5 ml, 43.5 mmol) was added dropwise.

EXAMPLE 2 EXPERIMENTAL SECTION

General Comments apply to Examples 2-8:

All reactions were carried out in an inert atmosphere unless otherwisenoted. Solvents were purified by established procedures.1,7-Bis(chlorotetramethyldisiloxy)-m-carborane (40) was obtained fromDexsil and used as received.1,7-Bis(chlorotetramethyldisiloxy)-m-carborane (40) has the followingstructure: ##STR22## 1,3-Dichlorotetramethyldisiloxane (50) was obtainedfrom Silar Laboratories or United Chemical Technologies and used asreceived. 1,3-Dichlorotetramethyldisiloxane (50) has the followingstructure: ##STR23## n-Butyllithium (2.5M in hexane), andhexachlorobutadiene were obtained from Aldrich and used as received.Thermogravimetric analyses (TGA) were performed on a DuPont 951thermogravimetric analyzer. Differential scanning calorimetry analyses(DSC) were performed on a DuPont 910 instrument. Unless otherwise noted,all thermal experiments were carried out with a heating rate of 10°C./min and a nitrogen flow rate of 50 mL/min.

EXAMPLE 3

Preparation of 1,4-dilithio-1,3-butadiyne: ##STR24##

A 50 mL three-necked round-bottomed flask was equipped with a stir bar,glass stopper, septum, and gas inlet tube. After the flask wasflame-dried, THF (5 mL) was injected and the flask was placed in a dryice/acetone bath. n-BuLi (10.6 mL of a 2.5M solution, 26.5 mmol) wasthen added and the mixture was stirred for 5 min. Subsequently,hexachlorobutadiene (0.99 mL, 6.3 mmol) was added dropwise via syringe.After completion of addition, the cold bath was removed and the mixturewas stirred at room temperature for two hours. The resulting dark brownmixture was used without further treatment.

EXAMPLE 4

Preparation of polymer (20') from 50/50 of (40)/(50), respectively(y'/y≈1.0): ##STR25##

A mixture of 1,4-dilithio-1,3-butadiyne (6.3 mmol) in THF/hexane wascooled in a dry ice/acetone bath. To this mixture a homogeneous solutionof (40) (1.43 mL, 3.15 mmol) and (50) (0.62 mL, 3.15 mmol) was addeddropwise over a period of 15 min. After addition, the cold bath wasremoved and the mixture was stirred at room temperature for two hours.The tan mixture was then poured into an ice-cooled solution of saturatedaqueous ammonium chloride (30 mL) with stirring. The resultingtwo-phased mixture was filtered through a Celite pad and the layers wereseparated. The aqueous layer was extracted twice with diethyl ether andthe combined organic layers were washed twice with distilled water andonce with saturated aqueous sodium chloride solution. The organic layerwas dried over anhydrous magnesium sulfate and filtered. Most of thevolatiles were removed under reduced pressure at room temperature andthe residue was heated at 75° C. for three hours at 0.1 mm Hg pressureto leave a viscous dark brown material (1.76 g). ¹ H NMR spectroscopyshows large peaks at δ (ppm) 0.2-0.4 corresponding to the --SiCH₃protons, and a broad resonance from δ (ppm) 1.2-2.8 corresponding to thecarborane protons in the polymer. ¹³ C NMR spectroscopy shows two peaksat δ (ppm) 0.30 and δ (ppm) 1.9 corresponding to the --SiCH₃ carbons, apeak at δ (ppm) 68.1 corresponding to the carborane carbons, and twopeaks at δ (ppm) 84.8 and δ (ppm) 87.0 corresponding to the twoacetylenic carbons in the polymer. Infrared spectroscopic (IR) analysisconfirms the presence of the acetylenic groups with a strong peak at2071 cm⁻¹. Other prominent peaks are present at (cm⁻¹): 2962 (C--H),2596 (B--H), and 1077 (Si--O). DSC analysis showed the principalexotherm at 321° C. (FIG. 1). Char yield (TGA)=82% (FIG. 2). Reheatingthe char to 1000° C. in air resulted in only˜0.3% weight loss (FIG. 3).Holding the sample at 1000° C. in air for one hour resulted in anadditional˜0.3% weight loss. The weight loss leveled off afterapproximately 40 minutes.

EXAMPLE 5

Preparation of polymer (20') from 25/75 of (40)/(50), respectively(y'/y≈3.0):

In the same manner outlined above, 1,4-dilithio-1,3-butadiyne (6.3 mmol)was reacted with a homogeneous mixture of (40) (0.71 mL, 1.58 mmol) and(50) (0.92 mL, 4.72 mmol). The usual workup gave a viscous dark brownmaterial (1.3 g) which slowly solidified into a sticky solid. DSCanalysis showed the principal exotherm at 299° C. (FIG. 4). Char yield(TGA)=76% (FIG. 5). Reheating the char to 1000° C. in air showed minimalweight loss (FIG. 6). Holding the sample at 1000° C. in air for one hourresulted in ˜0.3% weight loss.

EXAMPLE 6

Preparation of polymer (20') from 10/90 of (40)/(50), respectively(y'/y≈9.0):

In the usual manner, 1,4-dilithio-1,3-butadiyne (6.3 mmol) was reactedwith a homogeneous mixture of (40) (0.29 mL, 0.63 mmol) and (50) (1.1mL, 5.67 mmol). The usual workup gave a very viscous dark brown material(1.22 g) which slowly solidified into a sticky solid. DSC analysisshowed the principal exotherm at 289° C. (FIG. 7). Char yield (TGA)=73%(FIG. 8). Reheating the char to 1000° C. in air resulted in 1% weightloss (FIG. 9). Holding the sample at 1000° C. in air for one hourresulted in no additional weight loss.

EXAMPLE 7

Preparation of polymer (20') from 50/50 of (40)/(50), respectively(y'/y≈1.0) using the stepwise method:

A mixture of 1,4-dilithio-1,3-butadiyne (6.3 mmol) in THF/hexane wascooled in a dry ice/acetone bath. To this mixture compound (40) (1.43mL, 3.15 mmol) was added dropwise. After addition and without delay,compound (50) (0.62 mL, 3.15 mmol) was added dropwise. The addition ofboth components lasted approximately 15 min. Usual workup gave amaterial whose properties were virtually identical to those of thematerial described in the 50/50 homogeneous approach. Reversing theorder of addition (i.e. adding (50) followed by (40) also gave similarmaterial (20') wherein y'/y≈1.0.

EXAMPLE 8

Preparation of polymer (20') from 5/95 of (40)/(50), respectively(y'/y≈19.0) using the stepwise method:

In the usual manner, compounds (40) (0.14 mL, 0.31 mmol) and (50) (1.17mL, 5.98 mmol) were added sequentially to a mixture of1,4-dilithio-1,3-butadiyne (6.3 mmol) in THF/hexane cooled in a dryice/acetone bath. The usual workup gave a viscous, dark brown material(1.2 g) which slowly solidified into a sticky solid. DSC analysis showedthe principal exotherm at 290° C. (FIG. 10). Char yield (TGA)=66% (FIG.11). Reheating the char to 1000° C. in air resulted in 16% weight loss(FIG. 12). Holding the sample at 700° C. in air for one hour resulted inan additional 13% weight loss after two hours.

EXAMPLE 9

Preparation of Polymer Where A=phenyl and E=oxygen and y'/y=1

Cool a mixture of 1,4-dilithio-1,3-butadiyne in THF/hexane using a dryice/acetone bath. To this mixture add a homogeneous solution of1,4-bis-dimethylchlorosilylbenzene and 40 (equal molar amounts) dropwiseover a period of 15 min. After addition, remove the cold bath and stirthe reaction mixture at room temperature for two hours. Pour thereaction mixture into an ice-cooled solution of saturated aqueousammonium chloride with stirring. Filter the suspension through a Celitepad and separate the layers. Extract the aqueous layer twice withdiethyl ether and wash the combined organic layers twice with distilledwater and once with saturated aqueous sodium chloride solution. Dry theorganic layer over anhydrous magnesium sulfate and filter. Removevolatiles by heating (no higher than 75° C.) under reduced pressure toleave the polymer. Note that in the final polymer of this example,x=x'=1, n=n'=2, u=1, q=q'=10, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are--CH₃. Additional details for preparation of1,4-bis-dimethylchlorosilylbenzene are given by Sveda et al., in U.S.Pat. Nos. 2,561,429 (1951) and 2,562,000 (1951), each patentincorporated herein by reference in its entirety and for all purposes.Aditional details are given in U.S. Pat. Nos. 5,272,237; 5,292,779 and5,348,917, each patent incorporated herein by reference in its entiretyand for all purposes.

EXAMPLE 10

(ClSi(CH₃)₂ CH₂ CH₂ CH₂ CH₂ Si(CH₃)₂ CH₂ CH₂ CH₂ CH₂ Si(CH₃)₂)₂ CB₁₀ H₁₀C (100) ##STR26##

Prepare a THF solution of BrMgCH₂ CH₂ CH₂ CH₂ MgBr (200) from1,4-dibromobutane and two equivalents of magnesium. Add two equivalentsof dimethylchlorosilane to form HSi(CH₃)₂ CH₂ CH₂ CH₂ CH₂ Si(CH₃)₂ H.Treat this compound with catalytic amounts of benzoyl peroxide inrefluxing carbon tetrachloride to form ClSi(CH₃)₂ CH₂ CH₂ CH₂ CH₂Si(CH₃)₂ Cl (300). Treat a solution of (200) with one equivalent of(300) and one-half equivalent of ClSi(CH₃)₂ CB₁₀ H₁₀ CSi(CH₃)₂ Cl toform the target material (100).

Alternatively, exemplary compound (300) may be formed according to thereaction: ##STR27##

EXAMPLE 11

Preparation of Polymer Where E=A=--(CH₂ CH₂ CH₂ CH₂)-- and y'/y=1

Cool a mixture of 1,4-dilithio-1,3-butadiyne in THF/hexane using a dryice/acetone bath. To this mixture add a homogeneous solution of 300 and100 (equal molar amounts) dropwise over a period of 15 min. Afteraddition, remove the cold bath and stir the reaction mixture at roomtemperature for two hours. Pour the reaction mixture into an ice-cooledsolution of saturated aqueous ammonium chloride with stirring. Filterthe suspension through a Celite pad and separate the layers. Extract theaqueous layer twice with diethyl ether and wash the combined organiclayers twice with distilled water and once with saturated aqueous sodiumchloride solution. Dry the organic layer over anhydrous magnesiumsulfate and filter. Remove volatiles by heating (no higher than 75° C.)under reduced pressure to leave the polymer. Note that in the finalpolymer of this example, x=2, x'=1, n=n'=2, u=1, q=q'=10, and R¹, R²,R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃.

EXAMPLE 12

Preparation of thermoset (35) having the formula whrein y'/y=1.0:##STR28## wherein n=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom,an R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃. To obtain the thermoset(35) wherein the ratio y'/y is varied as desired, the correspondinglinear polymer of the structure (20) is used as the starting materialsubjected to either heat or light.

To form the compound of EXAMPLE 12, the linear polymer (20) whereinn=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom, y'/y=1.0 and R¹,R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃ was heated in nitrogen at 300°C. for 2 hours then at 350° C. for 2 hours and finally at 400° C., for 2hours. Between each isotherm, the linear polymer (20) was subjected to atemperature heating gradient of 5° C./minute. The thermoset (35) ofEXAMPLE 12 was formed in this manner. Approximately, 15 mg of linearpolymer (20) was converted to the thermoset (35) by the isothermicheating described above wherein about 13.50 mg of thermoset (35) wasformed. The TGA of the thermoset of this example in air is shown in FIG.13.

EXAMPLE 13

Preparation of thermoset (35), supra, having the formula whreiny'/y=3.0: wherein n=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom,an R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃. To obtain the thermoset(35) wherein the ratio y'/y is varied as desired, the correspondinglinear polymer of the structure (20) is used as the starting materialsubjected to either heat or light.

To form the compound of EXAMPLE 13, the linear polymer (20) whereinn=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom, y'/y=3.0 and R¹,R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃ was heated in nitrogen at 300°C. for 2 hours then at 350° C. for 2 hours and finally at 400° C., for 2hours. Between each isotherm, the linear polymer (20) was subjected to atemperature heating gradient of 5° C./minute. The thermoset (35) ofEXAMPLE 13 was formed in this manner. Approximately, 15 mg of linearpolymer (20) was converted to the thermoset (35) by the isothermicheating described above wherein about 13.50 mg of thermoset (35) wasformed. The TGA of the thermoset of this example in air is shown in FIG.14.

EXAMPLE 14

Preparation of thermoset (35), supra, having the formula whreiny'/y=9.0: wherein n=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom,and R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃. To obtain the thermoset(35) wherein the ratio y'/y is varied as desired, the correspondinglinear polymer of the structure (20) is used as the starting materialsubjected to either heat or light.

To form the compound of EXAMPLE 14, the linear polymer (20) whereinn=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom, y'/y=9.0 and R¹,R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃ was heated in nitrogen at 300°C. for 2 hours then at 350° C. for 2 hours and finally at 400° C., for 2hours. Between each isotherm, the linear polymer (20) was subjected to atemperature heating gradient of 5° C./minute. The thermoset (35) ofEXAMPLE 14 was formed in this manner. Approximately, 15 mg of linearpolymer (20) was converted to the thermoset (35) by the isothermicheating described above wherein about 12.75 mg of thermoset (35) wasformed. The TGA of the thermoset of this example in air is shown in FIG.15.

EXAMPLE 15

Preparation of thermoset (35), supra, having the formula whreiny'/y=19.0: wherein n=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom,and R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃. To obtain the thermoset(35) wherein the ratio y'/y is varied as desired, the correspondinglinear polymer of the structure (20) is used as the starting materialsubjected to either heat or light.

To form the compound of EXAMPLE 15, the linear polymer (20) whereinn=n'=2, u=u'=1, x=x'=1, q=q'=10, A=E=an oxygen atom, y'/y=19.0 and R¹,R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are --CH₃ was heated in nitrogen at 300°C. for 2 hours then at 350° C. for 2 hours and finally at 400° C., for 2hours. Between each isotherm, the linear polymer (20) was subjected to atemperature heating gradient of 5° C./minute. The thermoset (35) ofEXAMPLE 15 was formed in this manner. Approximately, 15 mg of linearpolymer (20) was converted to the thermoset (35) by the isothermicheating described above wherein about 12 mg of thermoset (35) wasformed. The TGA of the thermoset of this example in air is shown in FIG.16.

EXAMPLE 16

Formation of Ceramics from the thermosets having the general formula(35), supra:

Ceramics of thermosets having the general formula (35) are readily madeby heating the thermosets to about 1000° C. at a rate of about 10°C./minute either in a nitrogen or oxidizing atmosphere (e.g. air). Theceramics of each of the thermosets of EXAMPLES 12, 13, 14 and 15 weremade during the heating process entailed in obtaining the TGA plotsshown in FIGS. 13, 14, 15 and 16, respectively.

Patent application entitled LINEAR CARBORANE-(SILOXANE or SILANE)ACETYLENE BASED COPOLYMERS with named inventors Teddy M. Keller andDavid Y. Son having the docket Navy Case No. 76,339 filed on 07 Nov.1994 is incorporated herein by reference in its entirety and for allpurposes.

We claim:
 1. An organoboron thermoset polymer having a repeating unitrepresented by formula (I): ##STR29## wherein: (1) n and n' are integersfrom 1 to 12 and u, u', y, y' and y" are positive integers;(2) wherein##STR30## represent cross-linked alkenyl moieties and wherein n and n'are as previously indicated; (3) R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ areselected from the group consisting of saturated aliphatic, unsaturatedaliphatic, aromatic, fluorocarbon moieties and mixtures thereof; (4)##STR31## represents a carboranyl group; (5) q and q' are integers from3 to 16; (6) x and x' represent integers greater than or equal to zero;(7) A is selected from the group consisting of O, an aliphatic bridge,an aryl bridge and mixtures thereof; (8) E is selected from the groupconsisting of O, an aliphatic bridge, an aryl bridge and mixturesthereof; and (9) wherein E and A may be the same or different.
 2. Theorganoboron thermoset polymer of claim 1 wherein said carboranyl grouprepresents a carboranyl group selected from the group consisting of1,7-dodecacarboranyl; 1,10-octacarboranyl; 1,6-octacarboranyl;2,4-pentacarboranyl; 1,6-tetracarboranyl; 9-alkyl-1,7-dodecacarboranyl;9,10-dialkyl-1,7-dodecacarboranyl; 2-alkyl-1,10-octacarboranyl;8-alkyl-1,6-octacarboranyl; decachloro-1,7-dodecacarboranyl;octachloro-1,10-octacarboranyl; decafluoro-1,7-dodecacarboranyl;octafluoro-1,10-octacarboranyl and mixtures thereof.
 3. The organoboronthermoset polymer of claim 1 wherein said carboranyl group represents acloso-dodecacarboranyl group selected from the group consisting ofcloso-dodeca-ortho-carboranyl, closo-dodeca-meta-carboranyl,closo-dodeca-para-carboranyl and mixtures thereof.
 4. The organoboronthermoset polymer of claim 1 wherein said R¹, said R², said R³, said R⁴,said R⁵, said R⁶, said R⁷, and said R⁸ may be the same or different andwherein each said R¹, said R², said R³, said R⁴, said R⁵, said R⁶, saidR⁷, and said R⁸ represents a hydrocarbon group having up to 20 carbonatoms and being selected from the group consisting of alkyl, aryl,alkylaryl, haloalkyl, haloaryl and mixtures thereof.
 5. The organoboronthermoset polymer of claim 1 wherein said u, said u' and said y" areintegers from 1 to 1000 and said x and said x' are integers from 0 to1000 and said n and said n' are integers from 1 to 12 and having a ratioof y'/y being greater than zero.
 6. The organoboron thermoset polymer ofclaim 1 wherein said u, said u' and said y" are integers from 1 to 500and said x and said x' are integers from 0 to 500 and said n and said n'are integers from 1 to 10 and having a ratio of y'/y being between about0.0001 to about
 100. 7. The organoboron thermoset polymer of claim 1wherein said u, said u' and said y" are integers from 1 to 250 and saidx and said x' are integers from 0 to 250 and said n and said n' areintegers from 1 to 8 and having a ratio of y'/y being between about 0.01to about
 50. 8. The organoboron thermoset polymer of claim 1 whereinsaid u, said u' and said y" are integers from 1 to 100 and said x andsaid x' are integers from 0 to 100 and said n and said n' are integersfrom 1 to 6 and having a ratio of y'/y being between about 1 to about25.
 9. The organoboron thermoset polymer of claim 1 wherein said u andsaid u' are integers from 1 to 10 and said x and said x' are integersfrom 0 to 10 and said n and said n' are integers from 1 to 3 and havinga ratio of y'/y being between about 5 to about
 15. 10. The organoboronthermoset polymer of claim 1 wherein said u and said u' are integersfrom 1 to 6 and said x and said x' are integers from 0 to 2 and having aratio of y'/y being between about 8 to about
 12. 11. The organoboronthermoset polymer of claim 1 wherein said u, said u', said x, said x'are integers equal to 1 and said n and said n' are integers equal to 2and having a ratio of y'/y being about
 9. 12. An organoboron thermosetpolymer made by a process of producing the polymer having a formula (I):##STR32## wherein: (1) n and n' are integers from 1 to 12 and u, u', y,y' and y" are positive integers;(2) wherein ##STR33## representcross-linked alkenyl moieties and wherein n and n' are as previouslyindicated; (3) R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are selected from thegroup consisting of saturated aliphatic, unsaturated aliphatic,aromatic, fluorocarbon moieties and mixtures thereof; (4) ##STR34##represents a carboranyl group; (5) q and q' are integers from 3 to 16;(6) x and x' represent integers greater than or equal to zero; (7) A isselected from the group consisting of O, an aliphatic bridge, an arylbridge and mixtures thereof; (8) E is selected from the group consistingof O, an aliphatic bridge, an aryl bridge and mixtures thereof; and (9)wherein E and A may be the same or differentsaid process comprising thestep of: heating a linear polymer having the formula: ##STR35## wherein:(1) n and n' are integers from 1 to 12 and u, u', y, y' and y" arepositive integers;(2) ##STR36## represent acetylenic moieties; (3) R¹,R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are selected from the group consisting ofsaturated aliphatic, unsaturated aliphatic, aromatic, fluorocarbonmoieties, and mixtures thereof; (4) ##STR37## represents said carboranylgroup; (5) q and q' are integers from 3 to 16; (6) x and x' representintegers greater than or equal to zero; (7) A is selected from the groupconsisting of O, an aliphatic bridge, an aryl bridge and mixturesthereof; (8) E is selected from the group consisting of O, an aliphaticbridge, an aryl bridge and mixtures thereof; and (9) wherein E and A maybe the same or different;at a temperature, and for a time, sufficientfor cross linking of said acetylenic moieties of said linear polymer toform said organoboron thermoset polymer according to said formula (I).13. The organoboron thermoset polymer of claim 12 wherein saidtemperature of said heating stop is from 450°-45o° C. and said time isfrom 1-8 hours.
 14. The organoboron thermoset polymer of claim 12wherein said temperature of said heating step is from 200°-400° C. andsaid time is from 4-12 hours.
 15. The organoboron thermoset polymer ofclaim 12 wherein said temperature of said heating step is from 225°-375°C. and said time is from 2-24 hours.
 16. The organoboron thermosetpolymer of claim 12 wherein said temperature of said heating step isfrom 250°-350° C. and said time is from 1-48 hours.
 17. An organoboronthermoset polymer made by a process of producing the polymer having theformula (I): ##STR38## wherein: (1) n and n' are integers from 1 to 12and u, u', y, y' and y" are positive integers;(2) wherein ##STR39##represent cross-linked alkenyl moieties and wherein n and n' are aspreviously indicated; (3) R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are selectedfrom the group consisting of saturated aliphatic, unsaturated aliphatic,aromatic, fluorocarbon moieties and mixtures thereof; (4) ##STR40##represents a carboranyl group; (5) q and q' are integers from 3 to 16;(6) x and x' represent integers greater than or equal to zero; (7) A isselected from the group consisting of O, an aliphatic bridge, an arylbridge and mixtures thereof; (8) E is selected from the group consistingof O, an aliphatic bridge, an aryl bridge and mixtures thereof; and (9)wherein E and A may be the same or differentsaid process comprising thestep of: exposing to light a linear polymer having the formula:##STR41## wherein: (1) n and n' are integers from 1 to 12 and u, u', y,y' and y" are positive integers;(2) ##STR42## represent acetylenicmoieties; (3) R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are selected from thegroup consisting of saturated aliphatic, unsaturated aliphatic,aromatic, fluorocarbon moieties, and mixtures thereof; (4) ##STR43##represents said carboranyl group; (5) q and q' are integers from 3 to16; (6) x and x' represent integers greater than or equal to zero; (7) Ais selected from the group consisting of O, an aliphatic bridge, an arylbridge and mixtures thereof; (8) E is selected from the group consistingof O, an aliphatic bridge, an aryl bridge and mixtures thereof; and (9)wherein E and A may be the same or different;at a wavelength, and for atime, sufficient to cross-link said acetylenic moieties of said linearpolymer thus forming said organoboron thermoset polymer according tosaid formula (I).
 18. The organoboron thermoset polymer of claim 17wherein said wavelength of said exposing step is in the ultraviolet (UV)range.
 19. The organoboron thermoset polymer of claim 18 whereto saidtime of said exposing step is from about 1 to 100 hours.
 20. Aboron-carbon-silicon ceramic made by a method comprising the stepof:pyrolyzing an organoboron thermoset polymer having a repeating unitof formula (I): ##STR44## wherein: (1) n and n' are integers from 1 to12 and u, u', y, y' and y" are positive integers;(2) wherein ##STR45##represent cross-linked alkenyl moieties and wherein n and n' are aspreviously indicated; (3) R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are selectedfrom the group consisting of saturated aliphatic, unsaturated aliphatic,aromatic, fluorocarbon moieties and mixtures thereof; (4) ##STR46##represents a carboranyl group; (5) q and q' are integers from 3 to 16;(6) x and x' represent integers greater than or equal to zero; (7) A isselected from the group consisting of O, an aliphatic bridge, an arylbridge and mixtures thereof; (8) E is selected from the group consistingof O, an aliphatic bridge, an aryl bridge and mixtures thereof; and (9)wherein E and A may be the same or different.